1. Field of the Invention
The present invention relates generally to electronic multifunction devices with storage devices and more specifically to protection of storage devices from power supply cut offs.
2. Description of the Related Art
It is well known that when power supply is cut off during data writing to a hard disk medium, the sector to which the data is being written becomes damaged, thus affecting start-up of the system at the next power on. Therefore, most conventional multifunction or computer devices include a means for protecting the hard disk medium when power supply is cut off during the writing of data thereto. An example of a disk protection device is an auxiliary power supply and backup means disclosed in Japanese Patent Laid-Open No. 5-94237.
Another example of a disk protection device is disclosed in Japanese Patent Laid-Open No. 5-314631, which discloses a power supply connecting/disconnecting device for a magnetic disk drive unit. After a power cut off, this power supply device continues to retain power supply to the magnetic disk drive when it is determined that power cutoff will adversely affect recording and playback processes on the magnetic disk drive. The power supply device can be disadvantageous in that although the user can use a power switch to cut off power supply, the user must wait for an undetermined amount of time before power shut down actually occurs.
A further example of a disk protection device is disclosed in Japanese Patent Laid-Open No. 7-153172, which discloses a hard disk protective device for suspending access to the hard disk when instantaneous cutoff of power supply is detected.
Among others, one disadvantage of the above-mentioned conventional hard disk protection systems is that they are somewhat expensive particularly in light of the ever-increasing need for large amounts of data storage by today's data systems. Also, if back up of large amounts of data is required, system performance may be unduly compromised.